Struct FirstReducer 

pub struct FirstReducer;

First reducer - keeps the first non-null value

Once a value is set, subsequent updates are ignored.

Example

// Before: null
// Update: "first"
// After:  "first"
// Update: "second"
// After:  "first" (unchanged)

Trait Implementations

impl Clone for FirstReducer

fn clone(&self) -> FirstReducer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FirstReducer

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for FirstReducer

fn default() -> FirstReducer

Returns the “default value” for a type.

impl Reducer for FirstReducer

fn reduce<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, current: Option<&'life1 Value>, update: &'life2 Value, ) -> Pin<Box<dyn Future<Output = Result<Value, AgentError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, FirstReducer: 'async_trait,

Reduce the current value with the update value

fn name(&self) -> &str

Returns the name of this reducer

fn reducer_type(&self) -> ReducerType

Returns the type of this reducer